October 2018

CATARACT

Cataract editor’s corner of the world Complex case: Deaf monocular patient with a posterior polar cataract

by Rich Daly EyeWorld Contributing Writer

This image shows the anterior capsule being removed. The capsule opening was made with a femtosecond laser. The patient was under general anesthesia. The white posterior polar cataract can be seen on the back side of the lens. It was important to have a centered and appropriately sized capsulorhexis in case the capsule ruptured and it became necessary to place an IOL in the sulcus. With a good capsulorhexis, the optic could have been captured behind the anterior capsule if needed.

This image shows the final piece of the cataract about to be removed. Note the white “manhole cover” that is the posterior polar cataract near the phaco probe.

This image shows the intraocular lens within the capsular bag before the incisions were hydrated. A small, round remnant plaque can be seen against the posterior capsule. The plaque was left in the eye and not polished off as the capsule was likely to be thin in this area. The plaque will be removed using a Nd:YAG laser later if it bothers the patient.
Source (al): Kevin Miller, MD

The gift of sight is remarkable, and many of us take it for granted. We depend on our vision for so much that we do in our lives everyday, but some people truly require their vision to be able to communicate. Such is this case as presented by Kevin Miller, MD. He describes a monocular cataract patient who relies on his vision to be able to read lips as he is completely deaf. Dr. Miller navigates us through the nuances of this very interesting and challenging case of doing surgery on a deaf patient with one eye who relies on that eye to be able to communicate with the world. Read on as we delve into the nuances of this complex case.

Rosa Braga-Mele, MD,
Cataract editor

A deaf monocular vision patient needed a surgeon to preserve his little remaining vision and his only way to communicate with the world

Visually significant posterior polar cataracts are always complex surgical cases. But that condition may have been the least complex component of a patient referred to Kevin M. Miller, MD, chief, cataract and refractive surgery division, David Geffen School of Medicine, University of California, Los Angeles.
The 62-year-old cataract patient also had neurofibromatosis type 2, was bilaterally deaf, and limited to light perception in the non-surgical OS eye. A tumor in the vestibular section of his left ear caused a facial nerve paralysis, which left him unable to close his left eye. The result was corneal ulceration, scarring, and light perception vision.
“He was able to hear at one point so he learned to read lips. He also learned sign language. These communication skills require vision, however, and his vision for doing so had gone down steadily,” Dr. Miller said.
In the right eye, the patient had glaucoma with high pressures, significant cupping of the optic nerve, a tiny field of vision—16 degrees in diameter—and somewhat eccentric fixation.
He had difficulty closing his right eye as well, for reasons that were not clear. He had a 3 mm area of exposure when he blinked, unless he squeezed hard.
A visually significant posterior polar cataract in the OD was the final component.
“Essentially, he was sleeping with both eyes open and he had all the usual problems that you see in the corneas from the exposure, so it wasn’t even clear what was affecting the right eye the most,” Dr. Miller said. “The deck was stacked against him.”

Surgical issues

The 2.5 mm-plus posterior cataract occurred with congenital dehiscence in the posterior capsule, which left the possibility of a large capsular hole when that part of the cataract was removed.
The patient’s lack of hearing, which limited his communication to sign language, led Dr. Miller to prioritize the return of vision as soon as possible postop. That eliminated the use of a regional block and extended eye patching, which would have left the patient with no ability to communicate. Dr. Miller also wanted to avoid the remote possibility of optic nerve or artery damage from the use of a needle in the posterior orbit.
“When I perform surgery on a person who is monocular, I almost always use topical anesthesia,” Dr. Miller said. “Because of the complexity of the polar cataract situation and the total inability to communicate under the operating microscope, it was a no-brainer that we would be doing this case under general anesthesia.”
Dr. Miller told the patient preop he would wait until he was fully awake to remove the patch and see if he had some vision.
The posterior polar cataract led Dr. Miller to prioritize the creation of a perfectly sized capsulorhexis in case the posterior capsule blew out. That led him to use a femtosecond laser to ensure a perfect rhexis, despite the complexity of using it under general anesthesia.
Use of a femtosecond laser in a general anesthesia patient requires the surgeon to accommodate the tube coming out of the mouth. Additionally, generally anesthetized patients cannot fixate on the light of the docking device as it’s coming down and sometimes the eye rolls off to the side. “What you end up doing is moving the patient’s head under the laser gantry to get the eye pointing straight up toward the docking device as it’s being lowered,” Dr. Miller said.
During surgery, instead of a capsular rent, Dr. Miller found a small amount of plaque material. He left a little of the plaque on the posterior capsule after learning from previous attempts that polishing such material can rip open the capsule.
After placing a single-piece acrylic lens in the capsular bag, Dr. Miller closed and patched the eye. About an hour later, once the patient was fully awake, he took the patch off and the patient was able to see and sign to him.
Dr. Miller noted that no currently available single-piece acrylic lens would have been suitable for implantation in the ciliary sulcus in the event of a large posterior capsule tear. A round edge lens is essential for this space because it comes into contact with the iris.
“The beauty of femto is that the capsulorhexis is exactly sized and centered, so if I did have a rupture, I could put in my backup lens and capture the optic inside the capsulorhexis,” Dr. Miller said.
His backup lens was a three-piece collamer model with a 6 mm optic.

Postop care

Preop, the right eye’s best corrected vision was 20/40 –1. One day postop, the patient’s uncorrected vision was 20/40 ±2, and the patient viewed it as better than it had been in several years.
“Presumably it will be a lot better as it heals, depending on the extent of optic nerve damage, but clearly, he was much better postop day 1,” Dr. Miller said.
Dr. Miller had advised the patient against the immediate postop use of artificial tears to avoid contamination of the incision.
“Normally, I advise patients against putting anything into their operated eye that might flush skin bacteria onto the ocular surface,” Dr. Miller said. “Patients often drop artificial tears on the side of their nose and roll them into the eye, so contamination can happen. I tell patients to wait to use artificial tears until the end of the first week when the infection rate is much lower.”
A couple of days postop, the patient’s eye became very dry and he repeatedly called with complaints that he could no longer see.
“At that point, I recanted and let him go back to instilling artificial tears,” Dr. Miller said.
The patient’s inability to close his eye will cause dry eye and other problems. Dr. Miller’s ongoing treatment will include careful assessment of his cornea, tracking the glaucoma damage, and determining if there are other posterior segment or optic nerve problems.
“One-eyed patients are complicated, and I see a lot of them,” Dr. Miller said. “But I hadn’t previously encountered a deaf one-eyed patient with a posterior polar cataract, glaucoma, limited visual field, and exposure keratopathy. That made it interesting and challenging.”

Editors’ note: Dr. Miller has no financial interests related to his comments.